nat into same address

I have classic static NAT, two interfaces, outside, inside. I NAT

A1 - B1 A2 - B2

but I need one address to pass through without NAT. How can I do that? If ther is no NAT for IP will router pass it inside or drop it? Can I do

B3 - B3 translation, state sam address

ip nat inside source static B3 B3

thanks!

Which device do you own?

A Pix will pass it through only if there is an appropriate static command and an ACL. I router will pass it without any special entries.

Yes, but I once had problems with a Pix in cases where B3 was part of the networks of B or A.

Regards, Christoph Gartmann

Drx,

Please post: - Model information - All relevant configuration portions (include complete inside & outside interfaces)

J.Cottingim

cisco 2621, 12.3(10) ios

int atmpvc ip addr 10.1.1.1 ip nat outside !

int loopback0 ip addr 10.2.1.1 255.255.255.128 !

int fa0/0 ip addr 10.2.1.131 255.255.255.128 ip nat inside !

ip route 10.3.1.1 255.255.255.255 10.2.1.133 ip route 10.3.2.1 255.255.255.255 10.2.1.133

ip nat inside source static 10.3.1.1 10.2.1.11 ip nat inside source static 10.3.2.1 10.2.1.21 ip nat inside source static 10.2.1.133 10.2.1.133

I think it will work if you remove the line "ip nat inside source static 10.2.1.133 10.2.1.133"

so your are saying that if there is no NAT statement, engine will simply pass the packet?

yes... it will perform it's routing function. It will only NAT if you've told it what to NAT. Otherwise it will attempt to route.

If you want to NAT the rest of 10.3.1.0 /24? and 10.3.2.0 /24?... ... try adding...

ip nat inside source list 1 interface atmpvc overload access-list 1 permit any

This will NAT anything sourced from any IP address (other than the more specific NAT's) to the IP address of the ATMPVC interface.